Method and apparatus for continuously producing
spinnino dopes of spandex polymers



ClllA XR 1' 8641005 M g DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request or the applicant or owner in accordance with the Notice of Apr. 11, 186B, 849 00. 122i. Identiflcation is by serial number of the application and the heading indicates the number or pages or specification, including claims, and of sheets of'drawing contained in the application as originally died. The tile or this application is available to the public tor inspection; reproduction may be purchased for 80 cents per sheet.

Applications published under the Detensive Publication Program have not been examined as to the merits of alleged invention. The Patent Oflice makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED JULY 15, 1969 METHOD AND APPARATUS FOR CONTINUOUSLY PRODUCING SPINNING DOPES 0F SPANDEX POLYMERS William M. McSpadden, In, and Frederick W. Voigt, In,

both of E0. Box 511, Klngspor Tenn. 37662 Filed Nov. 20, 1968. Published uly I5, 1969 Int. Cl. CttBg 35/00, 22/04 [1.5. Cl. 260-775 I Sheet Drawing. 19 Pages Specification A method for continuously producing, in dope form, a spandex polymer having a relatively low Mw/Mn ratio including the steps of (I) initially preparing independent reactant solutions of the spandex prepolymer and the chain extender; (2) introducing the separate reactant solutions in a continuous manner to a mixing area; (3) intimately, rapidly and continuously mixing the reactant solutions in the mixing area; (4) flowing the mixed reactant solutions from the mixing area to a holdup area prior to the spandex reaction becoming more than 75% comf 1 u a 5 8 FY i6 27 2 t plete; and (5) permitting the intimately mixed reactant solutions to complete their reaction in the holdup area with no further agitation.

Apparatus including a mixing chamber with a high speed impeller, and including reactant inlets, a holding tank, and a connector between the misting chamber and holdup tank that is preferably adapted to provide plug flow between the chamber and the tank. The plug how is created by contraction of the discharge from the mixing chamber opening into the holding tank to produce a back pressure. The discharge from the holding tank is cemented to ametering pump for delivering the continuously formed spandex dope to one or more fiber thinning machines.

July 15, 1969 A w. M. MOSPADDEN. JR, ETAL DEF. Pua.

METHOD AND APPARATUS FOR CONTINUOUSLY PRODUCING SPINNING DOPBS F SPANDEX POLYMERS Filed Nov. 20, 196B .366. William M. M08:

Frederick W. V0 1 Lx'vux'rams can mar r/m',

ATTORNEYS 

